The present invention concerns a filter medium, a filter element, and a filter arrangement, in particular a passenger compartment air filter and a passenger compartment air filter arrangement for purifying air entering the passenger compartment of a motor vehicle.
Filter elements made from filter media serve for filtration of in particular gaseous media, for example, filtration of an air flow that is supplied to the passenger compartment of a motor vehicle. Even though applicable to any type of filter element, the present invention and the problems to be solved will be explained in the following with respect to a filter medium or filter element for filtration of air for the passenger compartment of a motor vehicle. Such filters are referred to in the following for short as vehicle interior filters.
Due to the increasing air pollution, in particular in metropolitan areas, in connection with the use of air-conditioning devices, it is desirable and also necessary to filter by means of suitable filters the air that is supplied from the exterior into the passenger compartment of a motor vehicle and is processed or air-conditioned. For this purpose, for example, particle filters or odor filters or alternatively also combinations thereof are conceivable which are to filter out the particles contained in the air as well as inherent smells of the ambient air or adsorb the substances contained in the ambient air as much as possible. Such filters for filtration of air for the passenger compartment of a motor vehicle are generally known in a plurality of embodiments and variants so that their configuration and function will be addressed in the following only briefly.
The employed filter media are also intended to remove pollutants, for example, dust and carbon-particulate matter as well as pollen, bacterial and fungal spores, bacteria and fungi. Some metabolic products of the microorganisms are known to constitute allergenic substances for the human body or its immune system. They can trigger allergic reactions, in particular in the area of the mucous membranes, for example, of the respiratory system, of the eyes or nose. Desirable is a filtration as comprehensive as possible of particles and other potentially harmful substances by the filter medium.
EP 1 882 511 A2 discloses, for example, a filter medium with bactericidal action, in particular for filtration of air for the passenger compartment of motor vehicles, comprised of at least one filter layer that filters out impurities and of a bactericidal filter layer downstream of said filter layer which is arranged at the clean side of the at least one filter layer and is spaced apart by a spacer layer from the at least one filter layer.
WO 2012168185 A1 describes a filter medium with antimicrobial action, in particular for filtration of air for the passenger compartment of motor vehicles, comprised of at least one first filter layer that filters out impurities and of a second filter layer neighboring said first filter layer. The second filter layer is attached to the inflow side of the first filter layer and contains antimicrobial materials.